People worsening the situation - coastal defences called groynes have been built at Mappleton. Groynes stop material from being moved further down the coast. This means the beaches are narrower and more easily eroded in some other places

Powerful waves - Holderness faces the prevailing wind direction, which brings waves from the north east (all the way from the Arctic Ocean). Waves increase in power over this long distance, so the coast is battered by highly erosive waves